1. Field of the Invention
The present invention relates to the field of beverage dispensers, and more particularly, beverage dispensers with pressure regulators for regulating the gas pressure from a gas cartridge to a beverage to be dispensed.
2. Prior Art
U.S. Pat. No. 5,022,565 discloses a soft drink dispenser which includes a regulator for receiving CO2 under a relatively high pressure from a CO2 cartridge and providing a regulated pressure to the beverage within a container connected to the soft drink dispenser. Because of the very limited space available for the pressure regulator, the regulator used a sliding regulator member sealed with respect to the regulator housing by an O-ring. Such a regulator construction has the disadvantage of the friction of the O-ring, compounded by unit to unit dimensional variations in the O-rings themselves, as well as the O-ring groove it fits into, and the diameter of the cylindrical surface in which it slides. These variations can result in undesired unit to unit regulated pressure variations for carbonated beverages. Too low a pressure will not maintain the desired carbonation in the beverage, whereas too high a pressure will tend to over-carbonate the beverage, causing an excessive rate of consumption of the CO2, and increasing the dispenser delivery rate, which together with the over-carbonation leads to excessive foaming in certain beverages and in general the loss of carbonation in the beverage which reaches the consumer's glass or cup.